Well, they're kinda the same thing, depending on the nuanced application.

In this card, @jordanhamilton shared a cool video about how you can use a lipstick to hack the hell out of your makeup technique and application.

What I noticed toward the end of the video was how to make your lips plumper, by taking a white eye shadow and dabbing it at the direct middle of your upper and lower lips. And from there, you simply pat it out and fade it.

If you're going for juicy lips, then this is the course of action (or at least one way). To get ombre lips, then you can do the same thing or do as other makeup artists, and add another color that is lighter than the base color to fade into an ombre. Keep in mind that ombre works best when there are three colors shading. Not two and try to avoid four. you don't want it to look like a clown's lips.

I kind of do this when I wear lipstick. It's actually a lip crayon by Clinique, in the color "broadest berry." I put on chapstick, then line the outside of my lips with the crayon, and rub together like normal, creating kind of an ombre look. I also love to line my lips with black liner and fill in with shiny pink lipstick, and rub together for Halloween. It creates a purplish color where the black and pink mix. It looks so pretty.